ABSTRACT
Aluminum chloride is a powerful neurotoxin involved in the development of neurodegenerative disorders like Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and strokes. These conditions are marked by symptoms such as memory impairment, cognitive decline, and cholinergic deficiencies. Aluminium's neurotoxic effects can lead to oxidative harm within the brain, triggering apoptosis and causing irreversible harm to neurons. Given that brain cells are notably vulnerable to oxidative injury due to their high oxygen utilization, it becomes imperative to regularly incorporate antioxidants into one's diet to safeguard against such neurological damage. Soybean, rich in antioxidants, possesses the capacity to both prevent and reverse this oxidative injury. The aim of this study was to investigate the effects of aqueous Soybean extract on aluminium chloride (AlCl3) induced toxicity in fruit fly (Drosophila melanogaster). Drosophila melanogaster were allocated randomly to four (4) treatment groups, each exposed to a specific concentration and combinations of aqueous soybean extract, and AlCl3. Group 1 served as control group and the flies where fed on 9.8g of cornmeal diet. Group 2 were treated flies fed on 40mM AlCl3 and 9.8g of cornmeal diet. Group 3 were treated flies fed on 2 mg/kg aqueous soybean extract + 40mM AlCl3 and 9.8g of cornmeal diet. Group 3 were treated flies fed on 2mg/kg aqueous soybean extract and 9.8g of cornmeal diet. A survival study was conducted for fourteen days, with a meal change every five days all administrations were done via mixing with the cornmeal diet. At the end of the survival study, their survival rates where recorded and measured. The neurobehavioural activity was recorded and evaluated using negative Geotaxis. At the end of the treatment period, the flies were anesthetized, weighed, and then homogenized. Subsequently, the homogenates underwent centrifugation and the resulting supernatants were carefully aliquoted into appropriately labeled Eppendorf tubes and used for the biochemical assays. Each of these assays was conducted in triplicate for all experimental groups. The biochemical assays conducted where; superoxidase dismutase (SOD), malondialdehyde (MDA) and acetylcholinesterase (AChE) for antioxidant activity. For the survival studies the results showed a significant decrease (p<0.05) in the survival rates of flies treated with AlCl3-only in contrast to the control group. The flies treated with soybean-only, showed a similar survival rate to control group, while the flies treated with a combination of AlCl3 and Soybean extract showed a significant increase (p<0.05) in survival rate compared to that treated with only AlCl3. Comparison of the climbing activity using negative geotaxis showed that the flies in AlCl3-only group, had significantly reduced (p<0.05) neurobehavioural function (i.e climbing activity) compared to the flies in control group and soybean group, while Soybean + AlCl3 group showed significant increase (p<0.05) compared to AlCl3-only group. Assessment of antioxidant activity (SOD) showed oxidative stress (low antioxidant activity) in flies of AlCl3-only group compared to control, while AlCl3 + soybean group showed no significant change when compared to AlCl3 group. There was significantly increased (p<0.05) level of MDA activity in the flies of AlCl3-only group compared to control and a significant decrease (p<0.05) in the level of MDA activity in that of soybean + AlCl3 group compared to AlCl3 group. The soybean-only group showed similar MDA activity level as control. Analysis of the acetylcholinesterase(AChE) activity showed a significant increase (p<0.05) in AChE activity in the flies in AlCl3-only group compared to the control group and soybean + AlCl3 group showed significant decrease (p<0.05) in AChE activity compared to AlCl3-only group. In conclusion, the findings showed that soybean was not toxic to the animals but protected and showed ameliorating effect against Aluminium chloride toxicity.This therefore provides the research evidence of the protective effect of aqueous soybean extract in aluminium chloride exposed Drosophila Melanogaster.
